| 释义 |
al·um
I. \ˈaləm\ noun
(-s)
Etymology: Middle English, from Middle French alum, alun, from Latin alumen — more at ale
1. : either of two colorless or white isomorphous crystalline double sulfates of aluminum having a sweetish-sourish astringent taste used chiefly in medicine internally as emetics and locally as astringents and styptics:
a. : the potassium double sulfate KAl(SO4)2.12H2O occurring naturally and also made commercially (as by treating bauxite with sulfuric acid and then potassium sulfate) : potassium aluminum sulfate — called also potash alum, potassium alum; compare alunite, kalinite
b. : the ammonium double sulfate NH4Al(SO4)2.12H2O made commercially (as from ammonium sulfate and aluminum sulfate) — called also ammonia alum, ammonium alum
2. : any of a series of double salts isomorphous with potash alum that may contain analogous elements in place of the potassium, aluminum, and sulfur
< soda alum >
< chrome alum >
< selenium alum >
— compare pseudoalum
3. : aluminum sulfate — used chiefly commercially
II. \əˈləm\ noun
(-s)
Etymology: by shortening
: an alumnus or alumna |